1. Field of the Invention
This invention relates to a method and apparatus for shaping elastic materials such as bread dough, and, more particularly, to a method and apparatus for producing a continuous sheet of bread dough.
2. Prior Art
In the prior art method for producing bread a large mass of dough, prepared by kneading flour, water, etc., by a mixer, is metered and then divided into small pieces of dough in the first process. Each piece is of the same weight as that of an end product. Sometimes the end product is very small. There are many inconveniences in this process in that when very small pieces of dough are to be formed at the beginning, the bread-making process is often complicated, errors in the weight of the products are large, the efficiency of the process is hindered, and the range within which the size of the products can be changed is limited.
Producing bread by first forming a continuous belt-shaped dough sheet and then dividing it into pieces of dough that are the size of pieces of bread has also been developed as prior art. However, due to the characteristics of the bread dough itself, namely, the gel structure of gluten and the high elasticity resultant from such structure, it has been difficult to produce a continuous belt of bread dough with sections of a uniform weight. Hence, such a belt of bread dough is conventionally produced by repeatedly passing bread dough between a pair of rollers and thus the elastic bread dough is forcibly moved and the gel structure is destroyed.
That is, this prior art method of producing bread dough is a way of plastic molding, in which rollers exert a repetitive application of force on the bread dough. This method is not suited for producing traditional high-quality bread comparable to hand-made bread. Thus, as mentioned above, in the method of the prior art, it is more often than not that after mixing the ingredients the bread dough is first divided into small round pieces. The dough pieces are then aged for a long time to restore the original gel structure of the protein. This effect is to be induced by an oxidizing agent that had been added in advance to the dough. The dough is then shaped and baked.
U.S. Pat. No. 4,629,110 discloses an apparatus for stretching dough in which a plurality of conveyors, each driven at a different speed, are serially disposed. It has a roller mechanism comprising a plurality of rollers that are freely rotatable about their axes, that constitute a straight path, and which are spaced apart from and located over the conveyors. Although in these prior art apparatuses the dough is smoothly stretched, the roller mechanism has a heavy and complex mechanism, so that it requires high production, maintenance, and repair costs. Therefore, an apparatus for stretching dough that is simple, functions steadily, and that has low production costs, has been desired.
Accordingly, one of the objects of this invention is to provide a method and apparatus for producing a continuous belt of bread dough without destroying the gel structure of the bread dough by allowing it to freely flow within the limit of its inherent elasticity.
Another object of this invention is to provide a method and apparatus for steadily and continuously supplying a belt-like bread dough sheet to continuously produce dough products.
Still another object of this invention is to provide a method and apparatus for producing a sheet of dough adaptable for the efficient production of dough products.